Berni,
A 2.6.23 should be uploaded to sid today - please test that when its
available and let us know if it also fixes this issue for you. In the
meantime, it would also be useful if you could test one of the 2.6.23
snaphots. See http://wiki.debian.org/DebianKernel for details on
accessing the snapshot builds.

Gladly but note that this prevents standard install:
The following packages have unmet dependencies:

linux-headers-2.6.23-1-amd64: Depends: linux-kbuild-2.6.23 which is a
virtual package.

I'll try the source package...

Yep...linux-source.2.6.23 is sweet too wrp shutdown and power off.
Berni